Figure A1.
Rock armor cross section for 2-D stability tests
Figure A2.
Geobag cross section for 2-D stability tests
Existing data and wave climate studies
One source of design wave information is a memorandum recommending
rehabilitation of the north jetty at the entrance to Grays Harbor (USAED, Seattle,
1974). The proposed design wave was 6.7 m (22 ft). This wave height was
developed assuming depth-limited conditions over the submerged end of the
jetty.
However, depth-limited breaking should not be assumed a priori for the
proposed spur. Also, morphological surveys of the north jetty area reveal that the
seabed elevation in proximity to the north jetty fluctuates as much as 5 to 10 ft
annually. Therefore, an offshore non-depth limited design wave is developed
based on the most recent available data. The design waves are transformed to the
project site by applying shoaling factors and checked for depth-limited breaking.
A range of water levels from mean lower low water (mllw) to mean higher high
water (mhhw) plus storm surge is included in the analysis to account for potential
variations in water depth and water level that are anticipated at the north jetty.
A3
Appendix A
Stability Analysis of a Submerged Spur, North Jetty, Grays Harbor, WA
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